Joint design of a 90° - 180° spokes pulse in pTX for 2D TSE imaging at 11.7 Tesla

Motivation: The 2D TSE sequence is widely used in clinical neuroimaging. However, at 11.7T, B₀ inhomogeneity and significant variations in B₁⁺ transmit field strength reduce image quality. Developing pulse design strategies to homogenize both excitation and refocusing is essential for performing 2D TSE at ultra-high field strengths. Goal(s): We propose a joint design approach to design the 90°-180° pulse pair. Approach: Three strategies are investigated : 1) double angle, 2) the scaling error penalty and 3) the joint design approach. Results: The simulations show that the joint design is a promising approach giving good NRMSE with a strict respect of the CPMG condition. Impact: The joint design appears to be a promising strategy, enabling the generation of excitation and refocusing pulses while enforcing the respect of CPMG condition. This is a key step toward enabling 2D TSE sequences at ultra-high fields.